Gas-turbine.



N. B. WALES.

GAS TURBINE.

APPLICATION FILED AUG.'21, 1912.

Patented Oct. 14, 1913.

2 SHEETS-SHEET 1.

mine ses N. B. WALES.

GAS TURBINE.

APPLICATION FILED AUG. 21, 1912.

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F a i M 6 J 2 4 p y N w WW. wy W d W i) am; sra'rns PATENT ihhhi-tleNATHANIEL B. WALES, .015 'EBOSTON, MASSACHUSETTS.

Gas-TURBINE.

"construction which can be operated efiiciently under variableloads andto this end I provide a plurality of independent, self- ,actuatedimpulse generators each of which can be worked at various speedsirrespective of the turbine shaft speed and can be cut-- out or thrownin as the casemay be, to govcm the power of the turbineandto adapt it toits load.

Another object ofitl e inyent on is, to provide generators which areself-actuated independently of each otherand to this end I provide meanswhereby each generator compresses its own working fluid to the; desiredextent and in sufiicient quantity as required by it without reference toany other generatorr Another object of the inyention is to provide agenerator adapted to generate high power in proportion to its weight andto this end I provide ,a generator, having a combustion chamber ofrelatively largeclearance volume.

.Other objects of the invention w ll he more specifically set forth anddescribed hereinafter. D Briefly my gas turbine comprises a tur bineWheel suitably connected to and operated by a plurality of independent,self-actuated impulse generators arranged in a,

circular plan. Each generator comprises a a suitable supply of air orgas and .a piston therein which piston is operated by thepressurc'generated in the combustion chamber after each explosion. Inorder to accomplish this result without aiiecting the efii-Specification of Letters Patent.

epplicatianfiled Augus 2 1 .12- al No 7 ,199-

Patented Got. 114, 1913.

ciency of the goneratorto any material extent I proyidea piston withinsaid combustionchamber which connected to or inteseal with the piston inthe compression ha the mer. p s on i g of relatively small area and justsuiticient to operate the compression piston'in the compression chamberand to overcome frictionof the mechanism. e

In the accompanying drawings showing the best mode of carrying out myinvention now knownto me, Figure 1 is a side eleva tion of ,a gasturbine constructed. and operated inaccordance with my invention andcombined with an electrical generator; Fig. 2 is a vertical sectionalView on line 2-2 in Fig. 1 showing the construction of a generatoradapted torusing a fluid fuel in combination with air under compressionand Fig. 3' is a vertical sectional view of a generator adapted forgaseous fuel.

Referring to the drawings illustrating the preferred embodiment of myinvention Fig. 1 shows a gas turbine directlyconnected to electricagenerator slot any well know n t u tion; \5 de ign ti g the turbine casgand 6- .thejenhaust ondui t ere .fllheturbine may be actuated by anynumber of generators butas shown in Fig. 1 it i YQ by. e ght indepen enselfeactuated impulse generato s a rang in .a ir r p an. m

1 Fig. .2, 7, designates a turbine wheel provided with suitable'buekets8 and mounted on a shaft 9 supported in a suitable thrust bearing 10.

The meter-red form of generator shown in the drawings comprises acombustion chamber 11, a piston 12 having access thereto, a compressionchamber 13 and a piston 14 therein. The pistons 12 and 14 may be 3 madeintegral as shown or may be independent- ,and connected so as to move inunison, order that the explosive pressure in the combustion chamber willdirectly operate the compression piston 14 The combustion chamber ll'ispreferably constructed with a clearance yolunie in excess of the volumeswept by the piston 12 and the area of the latter is so proportionedthat its resultant power is just sufiicien'tto operate the compressionpiston ,to compress the working fluid to its required pressure and toovercome the friction of the operative parts.

The compression chamber is provided with suitable intake valves 15through which is drawn the fluid to be compressed and with suitableexhaust valves 16 through which the compressed fluid is exhausted into areservoir 17 through a pipe 18. As shown in the drawings, thecompression chamber has two valves of each kind so as to compress bothon the upward and on the downward stroke of the piston. In some cases itmay be found preferable to compress the working fluid'on the upwardstroke only of the piston in which case but one intake valve and oneexhaust valve will be required. Any suitable valve of the automatic typemay be employed for these purposes. From the reservoir the working fluidunder compression is admitted to the combustion chamber 11 through avalve 19 at the proper time. At this point there is a slight differencein construction between the generator shown in Fig. 2 and thatillustrated in Fig. 3. The latter is designed to use a gaseouscombustible fluid and the former to use liquid fluid in connection withcompressed air and therefore in Fig. 3thevalve 19 admits to thecombustion chamber the gaseous fluid under compression and ready forignition but in Fig. 2 the valve 19 admits air under compression. In thelatter case the liquid fuel is sprayed into the combustion chamber atthe proper time through a valve 20 to produce the explosive fluid. Anysuitable ignition means may be arranged within the combustion chamber asfor instance a spark plug 21. Such portions of the combustion chamber asmay be necessary may be sur rounded by suitable water jackets 22.

In the construction shown in Fig. 2 where compressed air is used thereservoir 17 is preferably so made as to surround the combustion chamberand the turbine exhaust 6. This arrangement has a double advantage inthat the reservoir serves as a cooling jacket for the combustion chamberand other heated parts and the heat absorbed by the compressed airraises its temperature and increases the efficiency of thegenerator.

The combustion chamber 11 is provided with an exhaust opening 23communicating with an exhaust chamber 24 from which the gases flowthrough an exhaust valve 25 and opening 26 to the buckets 8 of theturbine wheel. The exhaust valve is made up of two disks 27 normallyseated in two openings in the valve casing 28 so that the valve is atall. times balanced. The valve is of such dimensions as to permit of afree flow of the gases to the turbine when the valve is open.

Any suitable means may be provided for operating the exhaust valve atthe proper times and one such means is shown in .the drawings in whichthe piston 14 is connected by a piston-rod 29 and a crank-arm 30 to afly-wheel 31. 'Upon the shaft of the flywheel is a beveled gear 32meshing with a similar gear 33 mounted on a shaft supported in a bracket34; the other end of the shaft carrying a beveled gear 35 meshing with abeveled gear 36'mounted on a vertical shaft 37 supported in a bracket 38and thrust bearing 39! The shaft 37 carries an eccentric cam 40 whichoperates the exhaust valve 25 through the medium of a valve stem 41. Aspring 42 maintains the valve in a normally closed position except whenit is held open by the cam. The gears 35 and 36 are so proportioned thatthe cam operates the exhaust valve at the proper time in the operationof the generator. To operate the valve 19 admitting compressed gaseousfluid into the combustion chamber or the valve 20 admitting liquid fuel,a cam 43 is mounted on the shaft 37, which cam operates the valvethrough the medium of a valve stem 44, a spring 45 serving to maintainthe valve in a normally closed position.

The valves of my generator are so de-. signed that the generator is inshort an enlarged clearance volume four cycle gas engine, the clearancevolume being represented by the combustion chamber 11 in which a largevolume of gas under pressure is ignited resulting in a large volume ofhigh pressure gas which is exhausted through the valve 25 onto theblades of the turbine 7.

The operation of my gas turbine is as follows: Taking the condition asshown in Fig. 2, the combustion chamber 11 is filled with an explosivemixture made up of compressed air which has been admitted through thevalve 19 and liquid fuel which has been sprayed through the valve 20. Assoon as the piston 12 has passed its lower dead center, a spark isgenerated by any suitable mechanism in the spark plug 21 therebyigniting the explosive mixture in the combustion chamber and forcingback the piston 12 in the usual manner as in a four cycle gas engine.Just before the piston 12 reaches its extreme upperposit-ion exhaustvalve 25 is opened by its cam 40 and the gas under pressure issuesthrough the valve to the bladesof the turbine. The pressure in thecombustion chamber is not materially reduced by the upward movement ofthe piston since the clearance volume of the combustion chamber is. muchlarger than the volume swept by the piston, and therefore approximatelythe full force of the explosive pressure is expended upon the turbine.The exhaust valve remains open for a period and when the pressure' inthe combustion chamber has fallen below the pressure in the reservoir17, the valve 19, which is automatic, opens and allows the compressedair to flow into the combustion chamber and out through the exhaustthereby scavaging the chamber, and forcing out the products ofcombustion. The operation of the exhaust imam? is so timed that it isheld 0 en a sutiicient period to permit of this result. In addition toscavaging the combustion chamber, the eompressedair also cools thechamber, the exhaust valve and turbine blades thereby preventingexcessive temperatures in those parts. During this time the piston 12has returned to the position shown in Fig. 2. The exhaust valve is thenclosed and the automaticvalve 19 remains open until the pressure in thecombustion chamber equals that in the reservoir 17 during which time thepiston has again receded. On its return it' compresses the contents ofthe combustion chamber to a slight degree and liquid fuel is sprayedinto the chamber and when the piston passes its dead center the mixtureis exploded.

In Fig. 3 I show a slight modification of Fig. 2 in so far as theimpulse generator is concerned, as follows: The intake valves 15 of thecompressor 13 are connected to a source of suitable gas, such as forinstance a suction-type gas producer. The gas enters through valves 15,is compressed in compressor 13 and passes through exhaust valves 16 intothe reservoir 17, which is con nected to a suitable intake valve 19which corresponds in all respects to the intake valve of a four cyclegas engine. In this form I show the combustion chamber 11 surrounded bya water jacket 22, in that I have no scavaging and cooling features asshown in Fig. 2, therefore I prefer to surround the combustion chamberas well as the exhaust valve, with a suitable water jacket. The exhaustvalve 25 is similar to the exhaust valve in a four cycle gas engine andthe mode of operation of the impulse generator, as shown in Fig. 3carries out the exact requirem'entsof operation of a four cycle gasengine. The intake valve may be variably governed, or the impulsegenerator may be speeded up or slowed down by a suitable throttle as ina conventional four cycle gas engine, or it may be varied in speed byadvancing or retarding the spark in the spark plug 21 so that the rateof impulses delivered to the turbine may be varied as desired. I havefound that it is best to run the impulse generator shown in Fig. 3 on alower number of impulses per unit number than in Fig. 2 so that theaverage temperature of the exhaust gas will not exceed a workabletemperature in respect to the turbine. This type of gas turbine isparticularly adapted to large power units such as those in powerstations for running a dy-- name and with a plurality of independentimpulse generators, one can always be kept in reserve so that if anyaccident happens to one of these in ordinary use, it can be immediatelystopped and the reserve one cut in without affecting the power developedin the turbine excepting during the time of change. Also this form ofgas turbine is especially desirable in that it can be so designed thatfor the average load there will be three or four generators idle and aspeaks come on during the rush hours of the day, reserve units can bethrown into operation thereby adapting itself to an over-load over thenormal output of the unit. This is particularly desirable in powerstation work and overcomes one of the great drawbacks in the ordinarygas engine which lacks flexibility and overload capacity.

Temperatures delivered by this apparatus compare in all respects toexhaust temperatures in the ordinary four cycle gas engine so that steelconstruction can be used without regard to abnormal temperatures.

It is to be noted that one of the important features of my invention isthat I am enabled to transform into kinetic energy which is utilized tocompress the succeeding charge of working fluid a small amount of theupper range of pressure generated in the combustion chamber at themoment of explosion thereby not materially reducing the pressure of thegases in the combustion chamber which are available for expansion on theturbine blades, together with the fact that, through the intermittencyof the cycle employed in the generator, my temperatures are no higher ormore severe on the turbine structure than those in the ordinary fourcycle gas engine.

My invention may be embodied in con structions other than that hereinshown and described and I desire to claim it broadly except where it isspecifically limited in the following claims.

I claim 1. A gas turbine comprising a turbine and a plurality of impulsegenerators each of which is independently actuated by its explosionpressure.

2. A gas turbine comprising a turbine and a plurality of independent,self-actuated impulse generators.

3. A gas turbine comprising a turbine and a plurality of independentimpulse generators in operative connection therewith; each of saidgenerators comprising a combustion chamber and means for compressing thefluid supplied to said combustion chamber, said compressing means beingoperated by the pressure generated in said combustion chamber after eachexplosion.

1. A gas turbine comprising a turbine and a plurality of independent,self-actuated impulse generators; each of said generators comprising acombustion chamber and means for delivering to said chamber fluid underpressure.

5. A gas turbine comprising a turbine in combination with a plurality ofindependent, self-actuated impulse generators; each -pawuma of saidgenerators comprising means for generatingintermittent impulses by theexplosion of a fluid under pressure.

6. A gas turbine comprising a turbine in combination with a plurality ofindependent, self-actuated impulse generators; each of said generatorscomprising means for generating intermittent impulses by the explosionof a fluid under pressure and means operated by said impulses forcompressingsaid fluid before it is exploded.

7. A gas turbine comprising a turbine in combination with a plurality ofindependent impulse generators; eachof said generators comprising acombustion chamber, a piston having access thereto and means actuated bysaid piston for compressing the working fluid before it is supplied tosaid combustion chamber.

8. A gas turbine comprising a turbine in combination with a plurality ofindependent, self-acting impulse generators; each of said generatorscomprising a combustion chamber, a compression chamber, a piston havingaccess to said combustion chamber and provided with means forcompressing the working fluid in said compression cha nmvam ing agreater volume than the volume of that portion swept by the said piston.

11. A gas turbine comprising a turbine in combination with a pluralityofindependent, self-actuated impulse generators; each of said generatorscomprislng a combustion chamber, havlng a clearance volume in excess ofthe volume swept by the piston, a piston having access to said chamberand means actuated by said piston for compressing the working fluidbefore it is supplied to said chamber. 7

12. A gas turbine comprising a turbine wheel and a plurality ofindependent, selfactuated impulse generators, each of said generatorshaving no mechanical connection with the turbine wheel and each compris-6o -ing a combustion chamber with a piston' having access thereto, saidpiston being actuated by the explosion pressure in said combustionchamber before said explosion pressure is given access to the turbinewheel,

and means for delivering to said chamber a working fluid under pressure.

13.'A gas turbine comprising a turbine wheel and a plurality ofindependent selfactuated impulse generators, each of said generatorshaving no mechanical connection with the turbine wheel and eachcomprising a combustion chamber, a piston having access thereto, andmeans whereby the pressure generated in said chamber after eachexplosion is utilized for compressing the next charge of working fluidbefore the pressure is given access to the turbine wheel.

In testimony whereof, I hereunto set my hand in the presence of twosubscribing witnesses, this the twentieth day of August,

NATHANIEL B. WALES.

Witnesses:

E. F. Nome, F. J. V. DAKIN.

